1. Field of the Invention
The invention relates to a rear suspension system for a vehicle, and more particularly, to a rear suspension system which can improve riding comfort, enlarge the inner space of the vehicle and enhance both controllability and stability at cornering by arranging two absorbing members respectively in a sub frame at front and rear portions of an axle.
2. Description of Related Art
Generally, a suspension system connects an axle with a frame and absorbs impact and vibration from roads to improve riding comfort and car safety.
The vertical connection of the suspension must be flexible to reduce impacts and vibrations from roads and the horizontal connection of the suspension must be strong to overcome the driving force, braking force and cornering force, all of which happen in the wheel.
The suspension system is classified into either a rigid axle suspension type or an independent suspension type.
Recently most of the cars adopt the multi-link type independent suspension since it has better riding comfort.
The multi-link type independent suspension includes at least four links which compose control arms, and it has a high free lay out degree.
Generally, the multi-link type independent suspension, as shown in FIG. 4, includes: a wheel carrier 100 which rotatably supports a wheel; an upper control arm 102 for connecting the upper portion of the wheel carrier 100 with a car body; a lower control arm 104 for connecting the lower portion of the wheel carrier 100 with the car body; a strut arm 110 formed as an assembly of a shock absorber 106 and a spring 108, the lower end of which is connected with the lower control arm 104 and the upper end of which suspends and supports the car body.
The above described conventional suspension system will have a variable mechanical feature in accordance with the arrangement or the length of each link, so it has a high free lay out degree.
The force applied to the wheel is distributed to each link, so it is possible to enhance both controllability and riding comfort.
The above conventional suspension system has a problem if it is adopted as a rear suspension system for a rear wheel drive vehicle because there is interference between a driving axle and a spring or a strut assembly, although it has no problem as a rear suspension system for a front wheel drive vehicle.
To solve the above problem, if the lower part of the absorbing member of the conventional suspension system is diverged into front and rear, then the axle can pass through the diverged space.
But, in this case, the upper part of the absorbing member should be raised thereby overshooting a value of the axle upon vibration of the wheel in order to prevent the axle from contacting the diverging portion, such that another problem happens, wherein the inner space of car becomes small.